Oscar Pistorius' so-called advantage

I can't wrap my head around this idea that Oscar Pistorius has an advantage over his fellow competitors in the Olympics.

Pistorius, who had both of his legs amputated below the knee before he turned 1, runs the 400 meters for South Africa.

I've read about the studies done on Pistorius and his prosthetics -- he can swing his legs faster because they're lighter, but the prosthetics take longer to get going at the start of a race (Sports Illustrated covered it in depth in this week's issue, but you need to be subscriber to get to the story at SI.com).

What I can't get past is how can someone who's missing the bottom of both of his legs have an advantage in anything?

Forget science. To me, the truest test of prosethetics will come when an able-bodied runner voluntarily has one or both legs amputated in order to gain the so-called advantage of using artificial devices.